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How to Solder: Beading

Introduction: How to Solder: Beading

This is my contribution to the "How to Solder Group", in an effort to get a fancy Instructables patch.

I have fidgety hands and subsequently find it quite hard sometimes to solder small joints, and so I invented a soldering technique I like to call "Beading". It involves making a small ball of lead solder and then placing it on the joint. But there's more to it....I guess...

Step 1: Materials, Tools and Other Misc Crap

My first major soldering project was a robot kit I got for Christmas this year, and I thouroughly enjoyed it, even though it only took me 2 days to complete. It was an "Escape Robot" Link as labelled by the packaging, and involved using infrared diodes that sent out signals which then bounced back off obstacles to the IR reciever back on the robot, in which case it would turn around and start moving again. It was quite interesting, seeing something I soldered and put some hard work into work so well. Of course there was some troubleshooting involving some weak, consequently broken solder points.

Tips

Questions

40 Comments

No, you are just either leaving your iron on too high of a setting or you are leaving it on while not using it. You get a brillo type pad you can scour the black stuff off while the tip is hot, but be careful, you can create microscopic gouges in the tip that will lead to a shortened tip life. The alternative is to use a soldering iron tip cleaner... heat the iron and dip the tip into the cleaner. Some say that leaving the tip with a good coat of solder can minimize this effect. Personally, I have been trying to do this, but I naturally wipe the tip almost every time.

Yeah, I figured that out... You might notice that the comment was a year old. Of course, I don't have a fancy iron with "settings", and I don't have a variac, so I just use the sponge and I use pliers to peel off the black layer.

The problem with this technique is that it bypasses the actual metallurgical properties that make soldering work. When you solder a joint, you're making a metallurgical connection. The solder actually flows into microscopic cracks in the metal of the two things that are being soldered together, forming a physical and electrical connection. When you just "paint" solder onto your components, you are essentially just using the solder as glue, and are making a weak and unreliable joint. Soldering correctly requires that you heat the two metallic objects you are joining rather than the solder itself. When the metals you are joining are heated, they allow the solder to flow into the microcrystalline cracks in the metal and create what is essentially a solid piece of metal. You should not melt the solder with your soldering iron, you should heat the components with your iron and melt the solder with the components.

hes right! you will get a cold joint if you use "beading" as you call it. AKA it will fall apart under little strain! and no, you didnt invent it. i used to do it that way, and guess what happened every time? i had to redo the joints 4 or 5 times before they would stay together right.

Even with very little soldering experience I see a major flaw in what you say. He is using it to solder small parts including electrical components. If you heat, say a resistor, lead to 500 degrees + you will most likely damage the component. The method of heating each component works best when soldering 2 pieces that can withstand the heat...not electronic components. Since the example of the robotic kit was used...the tutorial was based mainly around that.

I hate to have to be blunt here, but you're mistaken. The "method" of heating both pieces is how soldering works. Period. In order to solder sensitive components one would either use a variable-temperature iron, or be very cautious not to heat the component for more than a second or two. Most components can withstand the heat of soldering easily enough if you use an appropriately powered soldering iron - about 25 watts - and don't hold the iron on the component lead any longer than necessary.

The technique that was being described here is actually the mistake that many people who are just beginning to solder make. I made it myself when I first started soldering, but upon reading up on the appropriate techniques and methods, and the metallurgic science behind soldering, I learned I was doing it wrong. As with many things, the so-called "easier" method is often inferior to the "right" method.

When you do not heat both the component lead and the PCB pad to a sufficient temperature to melt the solder, a metallurgic bond will not be created between the two and you will have created what is referred to as a "cold" joint. While it may look like the board and component are joined with solder, and your multimeter may tell you that they are electrically connected, a cold joint can, and most likely will, cause problems with your circuit further down the road. "Painting" solder onto a joint with a hot iron as described is like using tape to fix a broken plate. While it may seem like the two pieces are attached to each other, they are actually just being held against each other by the adhesive, in this case the solder that has cooled around the joint. In order to form a proper solder joint that is both mechanically and electrically sound, the two pieces to be soldered must be heated enough that the liquid solder will flow into the microcrystalline fissures and cracks in the surfaces of the metals, thereby making both pieces of metal one continuous piece.

A cold solder joint may initially seem sound, but will cause problems eventually. The reason that this technique work on larger components that can withstand the heat is because this is how soldering works. If your component is so delicate that it is being damaged when you solder it you need to either replace it with a more robust component, acquire a variable temperature soldering iron, or reassess your soldering technique. Soldering most components such as resistors, capacitors, diodes, LEDs, transistors, and integrated circuits should not damage them. If, when soldered, the plastic of the components case is melting, then the component is being heated for far too long; much longer than should be necessary to form a good solder joint. If that is the case, the possible problem is with the soldering iron. Perhaps the tip needs to be cleaned or replaced, or isn't being tinned properly before making each solder joint.

There are numerous sites online with tutorials on soldering that will repeat exactly what I've said here. Here are a few links:

Hey Mightywhombat,
I spent 20 years working in an industrial chrome shop where I learned how to weld just about everything that can be welded, even plastic. However, the most difficult was welding lead anodes which requires one to maintain a very narrow heat range with one's torch. I concure with everything that you have said here although I might add that if you are soldering wires onto electrical connections, you can heat the wire first and apply solder to the wire then heat the do-dad that you are connecting the wire with until the two solder together.
lutherinski

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